We propose to continue our efforts to determine the composition and structure of EIM, in particular the dissociation of the aggregate to its subunits and reassociation with recovery of activity. New methods are developed for the reassociation and insertion of EIM into planar bilayers. While reconstitution of excitability has been achieved in bilayers by using a variety of lipids, thus far the proteins used for induction of excitability have all been of non-mammalian origin (EIM, alamethicin, monoazomycin and the polyene DJ 400B). All of these display the same voltage dependent conductance as the excitable systems of nerve or muscle. In order to achieve complete reconstitution of action potential, we will attempt to use our knowledge to develop methodologies for the isolation and characterization of the peptides or proteins responsible for excitability in mammalian nerve and muscle tissues.